Throttle control apparatus for locomotives



Oct. 19, 1954 J CANETTA ETAL 2,692,156

THROTTLE CONTROL. APPARATUS FOR LOCOMOTIVES F'lled July 24, 1948 3 Sheets-Sheet l 0t 19, 1954 J. cANl-:TTA Erm. 2,692,156

THROT'ILE CONTROL APPARATUS FOR LOCOMOTIVES Filed July 24, 1948 3 Sheets-Sheet 2 113. 2 84 85 8O 89 8i Q1 59 '74 55 16 Closing Pos.

7 Throttle Closed Pos'ion John Cornetto, Bxndrew T. Gorman /Z/ FuH Open 148 INVENTORS ATTORAE'Y Oct- 19 w54 J. CANETTA ETAL 2,692,156

THROTTLE CONTROL APPARATUS FOR LOCOMOTIVES Filed July 24, 1948 3 Sheets-Sheet 5 A INVENTORS 258 d0 hn C( LI LQG/ BYAndr'ew T. Gorman ATTORNEY Patented Oct. 19, 1954 THROTTLE CONTROL APPARATUS FOR LOCOMOTIVES John Canetta, Hempstead, N. Y., and Andrew T.

Gorman, Pitcairn, Pa., assignors to Westinghouse Air Brake Company, a corporation of Pennsylvania.

Application July 24, 1948, Serial No. 40,464

9 Claims. -1

This invention relates to locomotive control apparatus and more particularly to improvements in uid pressure controlled apparatus for controlling steam throttles on double engine locomotives.

In such apparatus, one operators control device usually is arranged to control the operation of two throttle adjusting motor devices, one for each engine, whereby the throttle of both engines may be opened or closed in unison and to equal degrees.

On locomotives of this type it has been experienced, when starting a train especially, that the front engine has a considerably greater tendency for slipping its wheels than the rear engine and with the usual throttle control apparatus, it is necessary when wheel slip occurs to reduce the steam supply to both engines in order to stop the wheel slip on the one engine.

It is therefore one object of our invention to provide an improved locomotive throttle control apparatus which will enable independent closing of the throttle on one engine of a two engine locomotive while the other throttle remains in any selected open position.

Another object of our invention is to provide an improved throttle control apparatus for two engine locomotives having operators control means for automatically closing the throttle on either engine, in case of slipping of the wheels thereon, while the other throttle remains open, and for a predetermined period of time after wheel slip is detected, to apply sand to the rail surfaces in front of the slipping engine wheels.

Still another object of our invention is to provide an improved throttle control apparatus for two engine locomotives having operators control means for simultaneously positioning a plurality of power control throttles, one on each engine, and for independently closing either throttle without changing the other, together with means for automatically closing the throttle on either engine in oase the wheels thereon should slip and to apply sand to the rail surface in front of the slipping wheels.

Other objects and advantages will appear in the following more detailed description of the invention.

In the accompanying drawings;

Fig. l is a diagrammatic view of a throttle control apparatus, embodying one form of the invention, for a two engine locomotive which provides independent manual closing of the throttle on either engine while the other throttle remains unchanged and which further provides for automatic sanding of the rail surface in front of the wheels of the engine upon closing the throttle thereon.

Fig. 2 is a diagrammatic view of the throttle positioning motor, shown in elevation in Fig. 1, with its parts in a normal or throttle closed position.

Fig. 3 is a plan view, with a portion broken away, of an operators throttle control valve shown in section in Fig. 1; and

Fig. 4 is a diagrammatic view of a throttle control apparatus embodying another form of our invention in which the closing of the throttle on either engine may be accomplished either manually without sanding of the rail surfaces, or the throttle on either engine may be automatically closed and the rail surfaces ahead of the respective engine wheels sanded when slipping starts.

Description-Figs. 1 and 2 As shown in Fig. 1, the throttle control apparatus therein illustrated may comprise two adjustable throttle valves I and 2, two throttle valve positioning motors 3 and 4, an operators throttle control valve device 5, a throttle closing valve device 6 and two sanding control valve devices 'I and '8.

The adjustable throttle valves I and 2 control the flow of power uid, such as steam under pressure or power fuel, from a supply pipe 9 to pipes I and I l which are arranged to convey the power fluid to, respectively, the propulsion means of two engines of a locomotive. Each throttle valve is operable to regulate o1` vary the amount of power fluid to the respective engine according to the adjustment of a lever I2 between a throttle closed position in which said lever is shown in the drawing, and a full open throttle position indicated by the broken line I3.

The throttle valve positioning motors 3 and 4 are similar in structure and each comprises a power portion I4 connected by a link I'5 to the throttle lever I2 of the respective throttle valve I, or 2, and a pilot portion I6 for regulating operation of the power portion I4 to position said throttle Valve in accordance with pressure of iiuid provided in a control pipe I'I connected to the throttle positioning `motor 3 or a pipe I8 connected to the positioning motor 4. The positioning motors 3 and 4 are substantially the same as that disclosed and described in the application of Harry C. May, Serial No. 550,691, filed August 23, 1944, and assigned to the assignee of the present application.

As shown in Fig. 2, the power portion I4 of each positioning motor comprises a casing containing a double acting piston I9 having at one side thereof a pressure chamber 29 and at the opposite side thereof a pressure chamber ZI. The chamber 20 is connected by a uid pressure control passage 22 to the pilot portion I6. The chamber 2l is connectedV byV a passage 23 to the pilot portion I and by a pipe 25 to the operators throttle control valve 5.

The piston I9 is firmly secured to one end of a piston rod 26 extending through the chamber 2| and a suitable packing gland 21 to the exterior of the casing. The exterior end of the piston rod 26 is connected by a pin 28 (Fig. l) to the respective link I5, the opposite end of which is pivotally connected by a pin 29 to the end of the respective throttle valve control lever I2.

Movement of the power piston I9 in its casing will rock the respective throttle control lever l2 for varying the supply of power iluid from the supply pipe 9 to the delivery pipe ID or II and to the respective engine. With the piston i9 in the position in which it is shown in Fig. 2, the respective throttle control lever I2 will `occupy the throttle closed or power off position in which position the lever is shown in Fig. l, while with said piston in contact with a shoulder 36 the respective throttle control lever` I2 will occupy its fully open throttle or maximum power position indicated by the broken line I3. By suitable adjustment of the power piston I9 between the two extreme positions just described, the respective throttle valve I or 2 may be correspondingly adjusted to provide any desired rate or flow of power iluid Yto the respective engine, as will be obvious.

A Coil spring 3I encircles the piston rod 26 in the chamber 2I and bears against the casing and theY adjacent face of piston I9 for moving piston I9 to the power 01T position, in which it is shown in Fig. 2, when fluid under pressure is released from the chamber 29. When uid is supplied to chamber 23 at a pressure sufcient to overcome the opposing force of spring 3l, the piston I9 will move against said spring for moving the throttle control lever I2 out of its throttle closed or power off position in the direction of the fully open throttle position, indicated by the broken line I3, to a position corresponding to the pressure of such fluid. A maximum pressure of iluid in chamber 26 will move piston I9 against spring 3l until the shoulder 39 engages the casing wall and will move the throttle to the fully open position.

The pilot portion I6 of each throttle positioning motor comprises a casing containing a ilexible diaphragm 32 at one side of which is a control chamber 33 connected by a passage 34 to the respective control pipe I7 or I8. At the opposite side of diaphragm 32 is a non-pressure chamber 35. Two casing bores 36 and 3'I are located at opposite sides of the diaphragm 32 and are coaxially aligned therewith. The bore 36 is open at one end to the chamber 35 and at the other end to the exterior of the casing. The Y bore 3'I is open at one end to chamber 33 and at the other end is open to one end of a larger bore 38, the opposite end of which is closed by a cap nut 38a.

A stem 39 extends centrally through the diaphragm 32 and is secured thereto for movement therewith. One end portion 46 of the stem 39 is slidably disposed in the adjacent end of the bore 35 while an opposite end portion 4I is arranged to slide with sealing engagement in the bore 37. The end portion 4I extending into bore 31'engages the smaller end of a plunger 42 slidably mounted in thebore 38. The larger end of the plunger 42 is disposedto slide with sealing engagement in the bore 38 to prevent leakage of uid pressure from a chamber 43, formed between the outer end of plunger 42 and .the cap nut 38a closing the end of bore 33 to the opposite side of said plunger which is open at all times to the atmosphere by way of a passage 44 in said plunger and a registering passage in the stem 3S, which latter passage opens to chamber 35. The chamber 43 is constantly connected by a passage 56 to the passage 22.

The end portion 40 or stem 39 disposed within bore 36 is provided with two spaced sealing rings 41 having sealing and sliding contact with the wall of said bore to prevent leakage of fluid under pressure past said sealing rings from an annular recess 48 provided in the peripheral surface of the end portion 46 `between said sealing rings. The recess 48 is open through a plurality of ports 49 to an annular cavity 55 in the casing and thence by a passage 5l to a uid pressure supply pipe 52 which may be constantly supplied with fluid under pressure from a supply reservoir 53.

The end portion 4e of stem 39 has a plurality of ports 48a connecting recess 48 to a central bore 54 extending into said stem from the end of said portion, a nut 55 being secured to said end for closing the end of said bore and having sliding engagement with the wall of casing bore 36. The nut 55 has an axial bore one end of which is open to a chamber 56 at the outer end ofthe nut while the inner end is open to the bore 54. Slidably mounted in the axial bore of nut 55 is a uted stem 57 projecting rfrom a' supply valve 58 contained in the bore 54 and arranged to seat against the inner end of said nut. A'precompressed bias spring 59 disposed in the bore 54 acts on the supply valve 58 for urging said valve to its seated or closed position as shown. The fiuted stem 5'I extends beyond the outer face of nut 55 into chamber 56 and therein engages a release valve 66 having a iluted stem 6I slidably mounted in an axial bore provided in a plunger 62. The plunger 62 is slidably disposed in bore 36 and is provided with two spaced sealing rings 62a having sealing and sliding contact with the bore 36 to prevent leakage of uid under pressure past said rings. An annular recess 63 is provided in the peripheral surface of the plunger 52 between the two sealing rings. The recess 63 is open through a plurality of radial ports 64a in the wall of bore, 36 to an annular cavity 64 in the casing and thence by a port 65 to the atmosphere. The recess 63 is also connected by one or more ports in the plunger S2 to a bore 63a therein into which the Vrelease valve stem 6I extends and, which contains a precompressed bias spring 66 acting on said stem for urging the release valve 66to an unseated or open position as shown. The pressure of spring 65 on the release valve 6I) however is less Ythan that of spring 59 on the supply valve 58. A plug 67 closes the outer end of the bore 63a in plunger 62, said plug having an adjusting screw 68 Vand a lock nut thereon for contacting said plug and locking the adjusting screw in an adjusted position. The outer end of the adjusting screw is adapted to bear against a lever 69, one end of which is mounted to rock on a pin I6 which is mounted in a xed arm II projecting from the casing. The opposite end of the lever 69 is operatively connected, exteriorly of the casing, to the power piston rod 26 by means of a lug 'I2 projecting from said lever into an annular groove 13 provided in said piston rod.

It will be noted that chamber 56 containing the release valve 60 is formed between the adjacent ends of the plunger 62 and the nut 55 and that said chamber is open to the passage 22 leading to the control chamber at the one side of the power piston I9 and by way of passages 22 and 46 to the chamber 43 at the outer face of plunger 42. It is desired to point out that the face of plunger 42, subject to fluid pressure in chamber 43, is of the same area as that of nut 55 subject to pressure of fluid in chamber 56, whereby the pressure of fluid effective in chamber 56 tending to urge the structure, including diaphragm 32, in the direction of the right hand will be counterbalanced by an equal pressure of fluid acting in the opposite direction in chamber 43 on the face of the plunger 42.

The chamber 35 contains a precompressed control spring 14 which encircles the stem 39 with one end -bearing on the casing, while the other end bears against a follower 'I5 which is provided on stem 39 adjacent the diaphragm 32. The spring 'I4 is operative to urge the stem 39 and the diaphragm 32 in the direction of the position in which they are shown in the drawing and which is defined by engagement with a casing stop 'I6 of a follower plate 'I1 secured to the stem 39. The spring I4 is designed to yield under uid pressure in chamber 33 and to cooperate with such uid pressure to define definite and different positions of diaphragm 32 and stem 39 corresponding to the pressure of such iiuid. Preferably the spring is precompressed to a degree which will move the diaphragm to the extreme right hand position as shown in Fig. 2 against a relatively low pressure of iiuid in chamber 33, such as eight pounds. The spring will yield and allow movement of the diaphragm and stem to the extreme left hand position in which further movement toward the left is prevented by reason of engagement of a shoulder 'I8 on the stem 39 with a stop 'i9 on the casing when a relatively high pressure of fluid is present in chamber 33, such as sixty pounds.

Each of the throttle positioning motors further embodies an insuring valve device 89 comprising a poppet valve 8l contained in a chamber 82 connected by a passage 83 to chamber 56, and

thence by passage 22 to the control chamber 29 at the right hand side of the power piston I9. The valve 8`I has a fluted stem 84 extending through a casing bore into a chamber 85 which is open to passage 86 and thence through chamber 64 and passage 65 to the atmosphere. The chamber 82 also contains a precompressed spring 81 which acts on valve 8l for urging it to a closed position.

In chamber 85 the iiuted stem 84 of the valve SI engages a stem 88 which slidably extends through a bore in a casing wall into a chamber 89 at one side of a piston 96 to which the stem is connected. The chamber 89 is continuously connected to the atmosphere by a port in the casing. At the side of piston 99 opposite chamber 89 is a pressure chamber 9| connected to the passage 23.

In operation, let it be assumed that the pressure of fluid in chamber 33 is initially eight pounds or less. The spring 'I4 is effective under this condition to move the stein 39 and diaphragm 32 to the position shown wherein the follower plate 'I'I engages the stop 16. The supply valve 58 is seated by spring 59 to prevent flow of uid under pressure from bore 54, and hence from the supply reservoir 53, to chamber 56 and by Way of port 22 to chamber 20 at the right hand side of the power piston I9. Spring 66 acting on the release valve stem 6I and the release valve 60 Will unseat said releaseV valve, for connecting chamber 56 and, hence via port 22, chamber 20, to the atmosphere by way of passage 65. With chamber 2U at atmospheric pressure, the spring 3I on the opposite side of piston I9 is effective to move the piston to the position shown, in which the throttle control lever I2 is positioned for closing the respective throttle valve I or 2 to cut oi the supply of power iluid to the respective engine.

Let it now be assumed that it is desired to admit power fluid to the respective engines for propelling same. To obtain this, uid under pressure exceeding eight pounds, by a degree proportioned to the rate it is desired that power iiuid be supplied to the engine, is supplied via .pipe II or I8 and passage 34 to chamber 33 at the right hand side of the diaphragm 32. This increased pressure of fluid acting on the diaphragm 32 is effective to overcome the opposing force of spring 'I4 and to deflect said diaphragm in the direction of and against spring 'i4 until the increasing force of the spring counterbalances the force of the increased pressure of fluid acting on said diaphragm. As the diaphragm 32 is thus moved in the direction of spring 14, the end portion 40 of stem 39 will move into chamber 56, first seating the release valve 66 by reason of theforce of spring 59 exceeding the force of spring 66, after which the supply valve 58 is unseated to admit fluid under pressure from the supply reservoir 53, via pipe 52, passage 5 i, chamber 50, ports 49, bore 54, past supply valve 53, to chamber 56 and from thence by passage 22 to chamber 26 at the right hand face of the power piston I9 and by passages 22 and 46 to chamber 43 on the face of plunger 42 where the force of the fluid pressure in chamber 56 against the stem 40 is counterbalanced. Fluid pressure admitted to chamber 20 is effective over the piston I9 to overcome the force of spring 3| and move the piston against said spring. Movement of the power piston I9 acts through the lever 69 to allow movement of the plunger 62 by pressure of uid in chamber 56 and by force of spring 66 in a direction away from the nut 55. Fluid under pressure is admitted to chamber 29 until the movement of piston I 9 moves the lever 69 to a position in which the accompanying movement of plunger 62 allows the supply valve 59 to seat and cut oir further supply of fluid pressure to chamber 26.

The movement of piston I9 in the direction of spring 3! is thus proportional to the movement of the diaphragm 32 against the control spring i4, this being proportional to 'the pressure of fluid in chamber 33.

It will thus be seen that upon a certain deiiection of diaphragm 32, as determined by the pressure ofuid provided in chamber 33, the power piston I8 will adjust the respective throttle control lever I2 out of its throttle closed position toward the full open throttle position in an amount proportional to the pressure of iiuid provided in chamber 33 in excess of the initial eight pounds.

If the throttle valve positioning motors are adjusted to any position in which the respective throttle valve l or 2 is less than fully open, the throttle opening may be increased by increasing the pressure of fluid in chamber 33 whereupon the positioning motor will operate to correspond- .7 ingiyifurther extend the power piston rod 26v and to increase the throttle opening by movement of the throttle control lever I2 in the direction of' the broken line I3 for supplying a corresponding increased amount of power iiuid to the respectivev engine.

If on the other hand, the operator desires a reduction in the amount of power duid supplied tothe engines, he will reduce the pressure of fluid acting in chamber 33, according to a desired reduction in power fluid. The spring 'I0 will then move the diaphragm 32 in the direction or" chamber 33 to a new ,and corresponding position in which the decreased force of the fluid pressure in said chamber is counterbalanced by the decreasing spring force. As the diaphragm 32 and the attached stem 39 are moved toward chamber 33, the supply valve 58 is carried with the stem and allows the spring 06 to unseat the release valve 50 to release iluid pressure in chamber 56, and hence in chamber 20, to the atmosphere. As fluid pressure is thus released from chamber 20, spring 3|, acting against piston I9 in opposition to the iiuid pressure in chamber 20, will move said piston in the right hand direction until the plunger 62 is moved against the seat of the release valve 60 by the motion of the lever 69. Y Y

The new position assumed by piston 20 will be one in which piston I9 does not engage the casing and the position of the lever I2 will be such as to control the power fuel supply propor-v tional to the pressure of fluid retained in chamber 33.

If the pressure of fluid in chamber 33 is reduced to or below the eight pounds, however, the movement of the power piston I9 by spring 3| toward chamber 20 will be complete, in which case the respective throttle control lever I2 will assume its full throttle closed position.

It will now be seen that any desired rate of supply of power uid to the'engines may be ob- Y tained by providing the proper pressure of uid in chamber 33 of the respective positioning motor 3 or 4.

In the above description of operation it will be noted that in each of the positioning motors 3 or 4, the movement of the power piston I9 and the adjustable throttle valve control lever 2 toward the throttle closed position upon release of iiuid p-ressure from chamber 20 is dependent upon and effected solely by spring 3|.`

Itis further noted that the spring 66 must unseat the release valve to release uid pressure ,from chamber 20 in order that the piston I9 can be moved to the throttle closed position.

To positively ensure the closing of the throttle in case of spring 3| being broken and to quickly close the throttle in emergency, iiuid pressure may be supplied from the operators control valve device in a manner to be explained later, by way of pipe 25 and passage 23 to chamber 2| to move the piston I9 to the throttle closed position. To insure this movement of piston |9, the fluid supplied to passage 23 is also effective in cham- "rov'e said piston in the direction of chamber 89, during which movement the plunger 38 engages the `valve stem 84 to unseat valve 8| and thereby open to atmosphere the power piston chamber 20 by way of passage 22, chamber 56, passage 83, passage 86, chamber 54 and passage 65.

The operators throttle control device 5, Fig. l, comprises a casing containing two coaxially aligned and spaced apart flexible diaphragms 92 and 93 of equal areas. A chamber `94 formed between the two diaphragms is connected by a passage 95 to pipe 52 and to the supply reservoir 53. At the opposite or lower side of diaphragm 92 is a chamber 96 which is open at lall times to the atmosphere through a breather opening 91. At the upper side of diaphragm 93 is a chamber 98 which is 'connected at all times by a choke 99 to a chamber |00. The chamber |00 is connected by a pipe |0| tothe throttle closing valve device 6.

The chamber 94 is divided by a partition wall I 02 which serves as a support for a control spring |03. Wall |02 is provided with a constantly open communication I02a to- .allow equalization of fluid pressures on both sides of the wall and also with a bore concentric with the diaphragms 92 and 93, and slidably mounted in this bore is a stem |04. Stem |04 is rmly secured to the central portion of diaphragm 92 by a follower |05, follower plate |06 and a nut |01 and is secured to the central portion of diaphragm 93 by a follower |08, follower plate |09 and a nut I I0.Y

The end of stem I 04 adjacent diaphragm 93 is provided with a chamber containing a valve II2 and spring |I3. Chamber II is open to chamber 94 by a plurality of ports I I4. A collar ||5 fits about stem |04 and against a shoulder on the stem and serves to transmit the force of the control spring |03 to said stem.

The nut ||0 is provided with a cylindrical extension IIS which is arranged to slide in a lbore in the casing wall separating chambers and |00, said bore being concentric with stem |04. The nut ||0 is further provided with a central bore connecting chamber ||I in stem |04 with chamber I 00. A fluted stem II'I attached to valve ||2 extends through Ythe bore in nut I I0 into chamber |00 anda seat for the supply valve 2 is provided on the nut about said bore.

A plunger I I8 is slidably mounted in an axial bore in the casing and extends into chamber |00 opposite the nut IIO. The plunger IIB is provided with a sealing ring having sealing and sliding contact with the surface of 'the casing bore to prevent leakage of fluid pressure from Y chamber |00. In the end of plunger H8 adjacent chamber |00 is an axial bore in which is slidably disposed a fluted stem ||9 ci a release valve |20 contained in said chamber, said plunger being provided with a seat for said release valve around the end of the bore adjacent said chamber.

The release valve |20 and its stem ||9 are arranged in coaxial relationship with the supply valve I I2 and its stem II'I Yand said release valve is urged into contact with the end of said supply valve stem by a spring |2I contained in a central bore of the plunger I I0. The end of spring I 2| opposite the release valve stem |I9 is supported by a cap nut` |22 which is firmly secured to the plunger I I8 to close the end thereof. The cap nut |22 extends beyond the cuter portion of the plunger-toprovidea seatfor a bias The bore in plunger H3 is open to the atmosphere at all times by a number of ports ||8a in the plunger adjacent the cap nut The pressure of spring 2| against the release valve stem I I 9 is less than the pressure of spring |I3 against the supply valve ||2 with the result that when plunger ||8 is moved in the direction of chamber |00, spring ||3 is effective to hold the supply valve ||2 seated and to support the release valve |20 against movement until said release valve is engaged by the valve seat on said plunger following which further movement of the plunger will act through said release valve to unseat said supply valve. Upon movement of plunger ||8 away from chamber |00 or upon movement of stem |04 and nut H0 away from plunger ||8 the spring ||3 is effective to maintain the release valve |20 seated until the supply -valve ||2 engages its seat on the nut |00. Spring |2| is effective to hold the release valve |20 in contact with the supply valve stem ||1 whereby the valve seat on plunger may move out of contact with the said release valve.

A handle |24 journaled on plunger ||8 and extending through an opening in the casing is adapted to be moved in a horizontal plane between a quick throttle closing position and a full open throttle position. Between these positions but closer to the quick closing position is a position which may be called a throttle closed position. See Fig. 3. 'I'he portion of handle |24 which encircles plunger ||8 serves as a support to the bias spring |23 and is provided with an upwardly extending cylindrical portion |25 encircling the spring |23 and provided with two oppositely arranged slots to receive two oppositely arranged legs of an inverted U-shaped member |21. The upper central portion of member |21 is arranged to receive a screw-threaded adjusting screw |28 which may be locked in an adjusted position by a lock nut |29. Each of the legs |26 is provided with an outwardly extending lug |30, the two lugs slidably engaging oppositely arranged and like cam surfaces provided on a ring |3| which is secured in the casing.

With the handle |24 in what is called the throttle closed position, in which it is shown in Fig. 1 of the drawings, the lugs |30 engage portions of the cam surfaces on ring |3| which permit the bias spring |23 to move the cap nut |22, plunger ||8 and the member |21 to a maximum upward position in which the supply valve |2 is held seated by spring ||3 and the release valve |20 is unseated by spring I2|. With the supply valve seated and the release valve unseated, chambers |00 and 98 and also the control pipe |0| are open to atmosphere past said release valve and through the plunger ||8.

If the handle |24 is moved from the throttle closed position in a counterclockwise direction toward the full open throttle position, the cylindrical portion |25 on the handle engaging the legs |26 on member |21 will turn said member relative to the ring |3| due to which the cam surfaces on ring |3| will move member |21 and thereby the cap nut |22 and plunger ||3 downward in the direction of the release valve |20. If this downward movement is greater than the clearance between the plunger ||8 and the release valve |20, the plunger will move into seated relation with said release valve and then move said release valve to unseat the supply valve ||2 to an extent corresponding to the degree of movement of the handle |24 out of the throttle closed position after closing of said release valve. Fluid under pressure supplied to chamber 94 from the supply reservoir 53 via pipe 52 will then flow past the unseated supply valve |2 to chamber |00 and thence to the control pipe |0| and also through choke 09 into chamber 08 to increase the uid pressure therein to act on diaphragm 93 in opposition to the pressure of control spring |03. The ilow of iluid under pressure to chamber |00 and to control pipe |0| continues until the fluid pressure established in chamber 98 is increased to a degree sufiicient to overcome the force of spring |03 and move the diaphragm 93 and thereby the stem |04 in a downward direction suilicient to seat the supply valve 2.

Assuming that movement of the handle |24 from the throttle closed position toward the full throttle open position was less than a maximum degree, the supply valve ||2 will be positioned so that movement of the diaphragms 93 and 02 and stem |04 against the force of control spring |03 by reason of increasing pressure in chamber 08 will be relative to said Valve until the nut |0 is moved into contact with said valve for preventing further ilow of uid under pressure past valve I|2 to chamber |00 and to the control pipe |0|. When the supply of fluid under pressure to chambers |00 and 98 and to the control pipe is thus cut off, limiting the increase in such pressure, movement of the diaphragm 93 and stem |04 will cease, since the increased pressure of spring |03 will counterbalance the pressure of fluid in chamber 98. The pressure of fluid in chamber 98 and in the control pipe |0| will thus be limited in accordance with the position of the supply Valve ||2 which in turn is determined by the extent of movement of the handle |24 from the throttle closed position toward full open throttle position.

If the previous movement of the handle |24 has been to a position less than full open throttle position, the operator may increase the pressure of fluid in chamber 98 and in the control pipe |0| by movement of the handle |24 further in the direction of full open throttle as will be apparent from the above description.

It will thus be seen that by suitable adjustment of the handle |24 out of the throtle closed position toward full open throttle position any desired pressure of iluid may be provided in the control pipe |0| and the pressure thus obtained may be obtained in iany desired number of increments.

Assume now that the control pipe |0| is charged with iluid under pressure as just described and the operator desires to reduce the pressure of such fluid. He will move the control lever |24 in the direction of the throttle closed position whereupon the lugs |30 are positioned on the cam surfaces of ring |3| to permit spring |23 to move plunger I8 in the direction of member |21. With the supply valve I2 seated prior to movement of the handle |24 toward release position, spring |2| will hold the release valve |20 in Contact with said supply valve and against movement with the plunger ||8 so that said release valve is unseated to connect chamber |00 and the control pipe ||l| to atmosphere. Fluid under pressure is then released from chamber |00 and pipe |0| and also from chamber 98 above diaphragm 03, and as pressure is reduced in this latter chamber spring |03 will move said diaphragm with stem |04 upwardly and spring I I3 acting on the supply valve ||2 will move said valve and the release valve in the direction of the plunger ||8. If the handle |24 is not moved to the throttle closed position, the plunger I8 will be stopped in a position in which movement of the diaphragm 93 and stem |04 by spring |03, and thereby the supply valve H2 and release valve |20, will be relative to said plunger until said release valve engages the valve seat on said plunger for preventing further release of fluid pressure from chamber |00 and pipe |0|. Upward movement of diaphragm 93 will then cease with the failure of fluid pressure in chamber Q3 to further reduce and the fluid pressure retained in chamber |35 and pipe will correspond to the position of the handle |24 out of its throttle closed position.

Movement of the handle into the throttle closed position. will result in plunger H8 being moved away from the release valve |23 sufliciently to allow full release of fluid pressure from chamber 93 and full extension of spring |33 without the diaphragm 93 moving far enough upward to cause said release valve to be seated against said plunger. It can thus be seen that iiuid pres sure may be reduced or increased in the control pipe I I in any desired increment and such pressure is determined by position of the handle |24 between throttle closed and full open throttle positions.

The throttle valve device further includes a quick closing valve device |32 which comprises a casing having a through bore containing a bushing |33 having a Xed and sealing engagement with said casing. The bushing |33 has an axial bore, one end of which terminates in a chamber |34 formed at one end of the casing bore which is closed by a cap nut |35. The chamber |34 contains a supply valve |35 having a stem |31 which has a sliding rit in the axial bore of bushing |33. A sealing ring |38 provided in the wall of the axial bore in bushing |33 provides a sealing engagement with the stem |31. Between the sealing ring |38 and the valve |35 is an annular chamber |39, said chamber being formed in the stem |31 and open by ports |40 to an annular chamber |41 surrounding bushing |33 and open to port 93 leading to pipe 52 and to the supply -reservoir 53 whereby the chamber |139 is adapted to be constantly supplied with uid under pressure. A spring |42 bears at one end against cap nut |35 with the other end bearing against valve `|36 for urging said valve to a seated position against the end of bushing |33 to normally prevent now of supply fluid pressure from chamber |33 to chamber |34.

The supply valve |36 and stem |31 are provided with an axial bore |43 one end of which opens to chamber |34 and the other opens to a chamber |44. Chamber |44 contains a release valve |45 arranged to seat against the stem |31, said valve having a uted stem |45 which has a sliding fit in the bore |43. Chamber |44 containing the y 'release valve |45 is open to atmosphere by ports |41 in a cap nut |43 closing the end of bushing |33. A plunger |49 extends from chamber |44 through a suitable bore in cap nut |43 for contact with a cam |53 on that part of handle |24 surrounding the plunger I I8. Cam |50 on handle |24 is arranged to close release valve |45 and to unseat supply valve |35 only when the handle |24 is moved clockwise from the throttle closed position into a quick throttle closing position.

4At all other times, pipe 25 connected to chamber |34 is connected to atmosphere past release valve |45.

When the handle |24 is moved into quickv Athrottle closing position, cam |53 acts through casing having chambers |5| and I 52 connected to the control pipe IGI. Chamber |51 contains a valve |53 having a luted stem |54 extending through a bore into a chamber |55k connected by pipe I1 and port 34 to control chamber 33 at one side of the control diaphragm 32 in the throttle valve positioning motor Chamber |52 contains a valve |56 having a fluted stern' |51 extending through a suitable bore into a chamber |53 connected by pipe |8 to the control chamber 33 of throttle positioning motor 4.

Extending through a bore into chamber |55 opposite valve stem |54 is a valve stern attached to a valve |53 located in a chamber |53. Chamber |60 is connected by way of a pipe iEI, cock |52 and pipe |63 to a volume reservoir |64 and also through a choke |65 to atmosphere. EX- tending through 'a suitable bore into chamber |53 opposite valve stem |51 is a valve stem attached to a valve |53 located in a chamber |61. Chamber |31 is connected by a pipe |68, a cock |39 and pipe |15 to a volume reservoir |1| and also to atmosphere through a choke |12. In chamber |55 a precompressed spring |13 acts against valve |59 to urge the valve to a normally seated position and to normally support valve |53 in an unseated position. In chamber |51 a precompressed spring |14 acts against valve |35 to support it in a normally seated position and to support valve |55 in a normally unseated position.

A plunger |15 extends from the upper side of the valve casing through a suitable bore into chamber |5I wherein it is adapted to engage valve |53. A sealing ring is provided in a cavity in the bore through which plunger |15 extends, said sealing ring being adapted to maintain a sealing engagement with both the casing and said plunger to prevent leakage of fluid pressure from chamber |5| to atmosphere. The outer end of plunger |15 is provided with a suitable operators push button |16 which is retained in a cavity in the valve casing where it is protected against accidental operation.

y The application of manual pressure to the button |16 causes plunger |15 to enter chamber I5| and to move valves |53 and |59 downward to a positionin valve |59 is unseated and valve |53 is seated. Release of button |13 permits closing or" valve |53 and opening of valve |53. It will therefore be seen that when the button |16 is relieved of manual pressure opening pipe |1 torpipe IBI, the operators control device 5 is rendered effective to control operation of the throttle control motor 3 and throttle valve to control the respective engine, while in case it is desiredto cut off the supply of power fluid to the engine in case of slipping wheels thereon, this may be accomplished by depressing the button |15 to clo'se communication between pipes lI and I1 and to release fluid pressure in pipe `I1 past valve |59 to pipe IGI and thenceV through cock |32 Veither to atmosphere direct or to volume reservoir |64 and to atmosphere through choke |85. This venting of uid pressure from pipe |1 reduces the control pressure in the throttle positionng motor 3 to atmosphere to cause the motor to close the throttle on the respective engine.

Releasing manual pressure `from the button |15 as after wheel slipping ceases permits spring |13 to return valves |59 and |53 to the position shown in the drawing wherein vcontrol uid `pressure from pipe IGI will again llow to pipe I1 and to the throttle positioning motor 3 ior eecting -openingof the. throttle on the respective engine I3 to the same degree as before depressing of button |16.

Similarly, a plunger |11 having an operators push button |18 extends through the casing into chamber |52 for the purpose of operating the valves |56 and |68 to either render the positioning motor 4 and throttle valve 2 controllable by the operators control device 5 independently of or in unison with the control of motor 3 and throttle valve or for, in case of slipping wheels on the respective engine causing operation of the positioning motor 4 and throttle valve 2 to cut o the supply of power to the respective engine in the same manner as above described in connection with depression of push button |16.

The cocks |62 and |69 are the well-known three-way type and when positioned as shown in Fig. 1 are adapted to permit automatic sanding of the rail surfaces in front of the wheels of the respective engines upon closing of the throttle valve or 2 by reason of operation of plungers |16 or |18 in the closing valve device v8. When fluid pressure is admitted to pipe |88 upon closing throttle valve 2 by depression of plunger |18, it flows to cock |69 and thence, with the cock in the position in which it is shown, to pipe |18 and volume reservoir I1 I and also to atmosphere through choke |12. If no sanding of the rail surface is desired the cock |69 will be positioned to disconnect pipes |68 and |18 and to connect the pipe |88 to atmosphere at the cock.

When fluid pressure is supplied to volume reservoir |1| it is also supplied by a pipe |19 to the sanding control valve 1.

The sanding valve device 1 comprises a casing enclosing a diaphragm |8| having at one side thereof a control chamber |82 open at all times to reservoir |1| by pipe |19. A chamber |83 provided at the opposite side of diaphragm |8| is open to atmosphere by a breather |84. Chamber |83 contains a follower |85 engaging diaphragm |8|. A shoulder |86 on the casing is provided for engaging follower |85 to limit the deflection of diaphragm |8| by pressure of fluid in chamber A spring |81 in chamber |83 acts on follower |85 to oppose the pressure of fluid in chamber |82.

The follower |85 is provided with a stem |88 extending through chamber |83 and a bore in the casing coaxial with diaphragm |8| into a chamber |89 connected by a pipe |98 to a fluid pressure supply reservoir |9| which may be charged with fluid under pressure from any suitable source. Stem |88 is provided with an annular groove to receive a retaining ring |92. A plate |93 is provided with a central bore and a recess of suitable diameter to receive the retaining ring |92. Before assembling the follower |85 and stem |88 into the casing, the spring |81 and plate |93 are placed over said stem and the spring compressed so that the retaining ring |92 can be placed in the groove in said stem to hold said spring compressed While the valve device is being assembled. Stem |88 is further provided with an annular groove within the casing bore to contain a sealing ring |88a to prevent leakage of fluid pressure from chamber |89 to chamber |83 and thence to atmosphere through breather |84.

The stem |88 is connected to a supply valve |94 to move said valve with said stem. The supply valve is contained in chamber |89 and has a fluted stem |95 which is slidably mounted in a bore |96 extending through a stem |91 of a valve |98 contained in a chamber |99 which is connected by a 4pipe 288 to a sanding reservoir 28|. The stem 75 |91 is slidably mounted in a bore coaxial with stem |88 and is encircled by a chamber 282the valve |98 controlling communication between said chamber and chamber |99. A sealing ring provided in a groove in the wall of the bore between chambers 282 and |89 slidably engages stem |91 to prevent leakage of fluid pressure from one chamber to the other. Chamber 282 is in constant communication with a pipe 283 adapted to be connected to a conventional sanding device operative when supplied with fluid pressure to apply sand to a rail surface. Chamber |99 contains a spring |98a which acts on Valve |98 normally urging it into a seated condition against the casing, to close communication between chambers |99 and 202.

In operation, normally chamber |82 is at atmospheric pressure by way of choke |12 and spring |81 acting against follower |85 supports the diaphragm |8| in the position in which it is shown in the drawing. In this position of diaphragm |8| and follower |85, the stem |88 is positioned to hold valve |94 from its seat on stem |91 and spring |9811 maintains valve |98 seated against the valve casing. Fluid under pressure in the supply reservoir 19| then flows past valve |94 through bore |98 to chamber |99, thence by pipe 288 to reservoir 28| to charge reservoir 28| to the pressure of fluid in the reservoir.|9

In case the operator presses button |18 of the throttle closing Valve 6 to cut oi the supply of power fluid to the respective engine as in case of slipping wheels thereon, fluid under pressure in pipe I8 and in the control chamber 33 of the throttle positioning motor 4 is vented to pipe |88 and thence by way of cock |69, when positioned as shown, and pipe |18 to reservoir |1| and through pipe |19 to diaphragm chamber |82 in the sanding valve device 1. A portion of the fluid pressure thus supplied to pipe |18 will be dissipated through choke |12, but the W capacity of this choke is such with respect to the amount of fluid supplied to said pipe and reservoir |1| to create a suflicient force in chamber |82 on diaphragm |8| to cause said diaphragm to move against spring |81'until the follower |85 engages shoulder |83 on the casing. During this movement of the diaphragm |8| and `follower' |85, the stem |88 will move the supply valve |94 into a seated positionv against stem |91 and will act against said stem to unseat valve |98. Communication from the supply reservoir |9| to the sanding reservoir 28| is thereby cut off by the supply valve numeral |94 and communication from the sanding reservoir 28| is established with chamber 282 and pipe 283 by valve |98. Fluid pressure in the sanding reservoir 28| then flows through pipe 283 to a sanding device (not shown) to cause sand to be applied to the rail surface before the wheels of the respective engine, whose throttle 2 was closed by depression of the button |18. Sand will thus be applied to the rail surface for a period of time which may be determined by the time for dissipating the fluid under pressure from reservoir 28| through the sanding device or by the release of uid pressure from reservoir |1| and control chamber |82 through the choke |12, it being apparent that the pressure of fluid in diaphragm chamber |82 will, after a certain lapse of time, become reduced through said choke to a degree at which spring |81 will actuate said diaphragm to permit closing of valve |98 and thereby cutting off of further ilow of fluid under pressure to the sanding device.

The sanding control valve device 8 is the same as and functions the same as the sanding control valve device 1 except it is controlled by operation of the push button |16, on the throttle closing valve device A6, for causing an independent closing of the throttle by motor 3.

- If it is desired that no sand be applied to the rail surface when the throttles are independently closed, the cocks |62 and |69 may be operated to a position in which pipes |6| and |68 are connected to atmosphere through said cocks without admitting fiuid pressure to the reservoirs |64 and |1| and to the sanding control valve devices 1 and 8.

It can now be seen that the throttle valves i and 2 can be simultaneously controlled by the operators control valve device 5 through the medium of pipe the throttle closing valve device Gand pipes l1 and |8, respectively. If, however,

- it becomes'necessary to close either of the throttle valve I-.or 2 to cut oi the supply of power fluid to the respective engine in case of slipping of the wheels thereon, this may be accomplished merely by depressing the respective push button- |16 or |18, it being noted that this cutting oi of the supply of power fluid to one engine by depressing button |16 or |16 has no eiect upon the supply to the Vother engine which remains under control of the operators control device. It will further be seen that upon release of button |16 or |18, as upon termination of wheel slipping, power uid will be resupplied to the respective engine by the operators control device 5 to the same degree as on the other engine.

Sanding of the rail surface in front of the wheels driven by the engine whose throttle is independently closed by depressing of button |16 or |18 may be either obtained at the same time the throttle is closed, or if desired prevented, by positioning of cocks |62 and, or, |69 to either open pipes |6| and |66 to the sanding control valves 1 and 6 or to atmosphere direct.

Description-Fig. 4

The .embodiment of our invention shown in Fig. 4 of the `drawings includes an operators throttle control valve device 5, two throttle valve positionng motors 204 and 205, a throttle closing valve device 206, two sanding control valve devices 1 'and 8, and two wheel slip detecting devices 201 and 208.

The operators throttle control valve device 5 is the same as that shown in Fig. 1, and described above.

l The throttle positioning motor 204 comprises a power portion 209 and a pilot portion 2|0. The power .portion k209 is the same as the power portion |4 of the positioning motor shown in Fig. 2. Briey, the power portion 209 comprises a casing having a bore in which a double acting piston-2 is located, said piston being operatively connected by a piston rod 2|2 and link I5 and lever I2 to a throttle valve (see Fig. 1) for controlling operation thereof. A control chamber 2|3 at one side of piston 2| is connected by a passage 214 to the pilot portion 2 I9 which, as explained hereinafter, controls the uid pressure therein. A chamber 2|5 containing a closing spring 2|6 is connected to the pilot portion by a passage 2|1.

The pilot portion 2|0 comprises a control diaphragm 2|8 clamped at its periphery in the casing and secured at its central portion to a control stem 2|9 which is arranged to cooperate with a plunger 220 to control an application valve 22| and a release valve 222 for regulating supply of fluid pressure to or release 'of fluid pressure from chamber V2 I3 for controlling the position of piston 416 2| l and hence the degree of Aopening of the throttle valve in accordance with the degree of control iuid'pressu-re supplied to a. control chamber 223 at one-side of said diaphragm.

The pilot portion further comprises an interccpting valve portion comprising a slide valve 224 contained in a chamber 225 formed in the casing by a piston 226 of one diameter and a piston 221 of a larger diameter. Pistons 226 and 22.1 are connected by a stem 228 extending through chamber 225 and provided with a recess to receive the slide valve 224 for causing movement of said slide valve by and with said pistons. A chamber 229 is located at the side of piston 221 opposite chamber 225 and is connected to the latter chamber by a passage 230 and a choke 23|. Chamber 229 is also connected by a passage 232 and a pipe 233 to the sanding valve device 1 and by pipe 234 to the Wheel slip detector device 201.

A piston 235 of a diameter larger than piston 221 is solidly secured by a stem 236 to piston 226. A chamber 231 formed in the casing by pistons 226 and 235 is open to atmosphere through a port 265 in the casing. A chamber 239 is formed at the face of piston 235 opposite chamber 231, said chamber 239 being open at all times through a passage 240 and a pipe 24| to Vthe closing valve device 206.

The slide valve 224 contains cavities 242, 243, 224 and port 245. Cavity 242 is adapted to connect passage 244 from the control chamber 2|3 at one side of piston 2|| to a passage 246 leading to a chamber 241 located between the stem 2|9 and the plunger 220 containing the release valve 222, in one position of the slide valve 224, .and to connect passage 2|4 to an atmospheric passage 241e in a second position of the slide valve, said second position to be attained as described later.

Cavity 243 Yin the slide valve 224 is arranged in the position of said slide valve in which .it is shown in the drawing to connect Ypassage 2i1, open to chamber 2i5 at the spring side of piston 2||, to the atmospheric passage 241m. In the second position of slide valve 224 cavity 243 is adapted to connect passage 2|1 to a passage `vof the control diaphragm 2|8 to a passage 252 leading to a control pipe 253 which is connected to the operators throttle control valve 5 whereby the control valve device 5 may control the iiuid pressure in the control chamber at the face of diaphragm 2|8. In the second position of slide valve 224, cavity 244 connects passage 25| to passage 254 which is a branch of passage 241a leading to atmosphere while port 245 connects passage 246 and the release valve chamber 241 to said cavity and thus to atmosphere.

In operation, uid from the supply reservoir 256 is sup-plied direct to the slide valve chamber 225 via pipe 229, rand passages 248 and V255 Wherein it acts against adjacent sides of pistons 226 and 221. Fluid under pressure in chamber 22.5 flows Via port 236 and choke 23| to chamber 229 at the side of piston 221 opposite chamber 225 to thereby charge chamber 229, pipes 233 and 234 the control chamber of the sanding Valve device 1 and a valve chamber in the wheel slip4 l? atmospheric pressure via kpassage 2&9 andy pipe 24|' as will hereinafter be explained. As can now be seen, the fluid pressures acting on opposite sides of pistons 221' .and 235V are balanced, While piston 226 is subject to .fluid at supply pressure in chamber 225 and to atmospheric pressure in chamber 23l which creates a force. to bias pistons 235, 225 and 2.2i and thereby slide valve 22d to the position in Which it is shown in the drawing and which is determined by the. engagement of L pistons 221 and .235 with the casing.

As Will be explained hereinafter, fluid pressure in chamber 229 is automatically vented by the Wheel slip detector 201 When wheel .slip occurs. When chamber 229 is thus vented, the, opposing lluid pressure forces on both pistons 2.25 and 22l are unbalanced and since piston `22'! is of larger area than piston 22e` the differential of forces across piston 22? exceeds the differential of forces across piston 22e and Will actuate piston 223' to move the several pistons and slide valve 224 toward chamber 22s until piston 22T engages the casing. As the slide valve 222 isv moved to this latter position, the control pipe 253 is disconnected from the control chamber 223 and said chamber 223 is. connected to atmosphere via passage 25|, cavity 2M and passages 254 and 2Mo. At this same time, fluid pressure in chamber 2|3 acting on the face of piston 2H is vented to atmosphere via passage 2M, cavity 222 and passage 2Mo and fluid under pressure is supplied to chamber 2|5 at the spring side of the power piston 2I| via passage 228, cavity l2433 and passage 2|?, to e'ect movement of piston 2|! and thereby of the throttle operating lever to atmosphere by cavity 243, chamber 2|3 at the l other side ci piston 2 ll is connected to chamber 22'! between stem 2li? and plunger 226, and the control chamber 223 at the face of diaphragm 212 is connected to fluid pressure in the control pipe 253. y

- When both chambers 225 and 229 are charged with ilui-d' at supply pressure and fluid under pressure is supplied to chamber 239 by a manual operation to be explained later, the fluid' pressure forces across pistons 235 and 226 are unbalanced with the greater force acting on the larger piston 235 in the direction of chamber 23"! ini opposition tothe force of fluid pressure in chamber 225 acting onpiston 225. This greater force on piston 2135 will then move said piston and pistons 222 and 221 with slide valve 224 toward chamber 229 until piston 221 engagesA the casing, which, as explained above, Will cause movement of piston 2 l to throttle closed position.

When pressure of fluidin chamber 239 is reducedto atmospheric pressure and while chambers 225l and 229 remain charged with fluid pressure, pistons 235', 226 andv 22? with slide valve 225' willbe returned to the position in which they are shown in the drawing for rendering the power portion 2129 of the throttle positioning motor controllable by the operators control device 5; through the control pipe 252i.

' The throttle closing valve device 292 is thesarne in construction as' the throttle closing valve and .|61 .are connected by a port 255i. Chambers '|52 and 1'5"! are open at all times to fluid supply pressure in pipe 249. Chambers li and |52 are open at all times by a pipe 251 to the quick clos'- ing valve |32 of the operators throttle control valve device `5. Chamber |55 is open by pipe 24| and passage 249 to chamber 239 of the throttle positioning motor device 294 and chamber |58 is open by a pipe 253 to a chamber, `corresponding to chamber 239 in motor 222i, in the throttle positioning motor 205.

It can now be seen that both positioning motors 2M and 205, can be caused to operate to a throttle closed position by operating the operators throttle control valve device 5 to the quick throttle vclosing position .in which fluid pressure is supplied to pipe 25T thence past valves of the throttle closing valve device 228 to pipes 24! and 251iI the throttle positioning motors lto effect closing of both throttle valves l and 2.

It can also be seen that either push buttons .|16 or |18 may be operated to effect individual operation of the respective throttle positioning motor 204 or 225 and the closing of the throttle valve associated therewith.

The sanding control valve devices l and 8 may be constructed the same as the sanding control valve device 'l and S shown on Fig. 1. In the embodiment shown in Fig. 4, the supply reservoir lili is, however, connected to chamber 222 in the sanding control valve device and pipe 223 through Which fluid pressure is supplied to effect sanding of the rail surfaces is connected to chamber |89.

Normally, the pipes 233 at both engines lare charged with uid under pressure to eieet operation of the respective sanding control valves l" and to permit flow of fluid pressure from the supply reservoirsv |9| to the sanding reservoirs 29|. When huid pressure is vented from either pipe 233 by the wheel slip detector 2t? or 208, as will be explained in connection with the description of the Wheel slip detector device, the respective sanding valve 'I or 8 will operate to cut off llow of fluid pressure from the respective supply reservoir i9| to the respective sanding reservoir 22| and to allow fluid pressure in said lsanding reservoir to flow to the respective pipe 265i to effect sanding of the rail surface.

The Wheel slip detecting devices 221.-' and 293 may be of' the type dis-closed and claimed in Patent. No. 2,447,709, issued August 24, 1948 to Joseph C. McCune.

Essentially, each of these. Wheel slip detector devices comprises a flyewheel or rotary inertia element suitably journaled for rotation vand adapted to be driven by an axle of the locomotive driving Wheels in such a manner that when. ever a certain rate of change oli driving speed of the axle occurs, a corresponding. rotational displacement of the ily-Wheel with respect to its. journal eiected to. cause unseatirrg of a. normally seated vent valve which., asf applied to the. present invention., will' effect. a venting of fluid. pressure from pipe 234 to the atmosphere:

In operation, sudden acceleration ot a driven axle on either locomotive engine above a certain rate, as occurs when; the Wheels. slip as the result ofthe application of too. much: driving force, will cause the wheel slip detector device 201 or 295 associated with the slipping Wheels to function to vent'lluidl pressure from the respectiveY pipe 234 to the atmosphere. Each pipe 232i1 is in direct Summary It will now be seen that we have provided in the apparatus shown in Figs. 1 and 2, a simplied pneumatically operated throttle control for two engine locomotives wherein the operator is enabled by a single control valve to control two throttle control motors and thereby the power of both engines in unison or he may, by the simple operation of pressing one of two buttons, selectively effect a quick and positive closing of the throttle valve on either one of the engines without affect on the throttle valveof the other engine. This he may do to permit the slipping wheels on either engine toreturn to rail speed While the other engine continues to work uninterruptedly. As soon as the wheel slip condition is corrected, the operator can remove the pressure on the selected button and the respective closed throttle valve will be returned to its open position as determined by the position of the operators throttle control valve handle.v

The apparatus also embodies rail sanding means, which, if desired, will automatically operate, in response to depression of the button for cutting off the power of either engine, to sand the rails for increasing traction o slipping engine wheels to aid in stopping slipping thereof.

The apparatus shown in Fig. 4 embodies a throttle control equipment incorporating the same operational functions of the apparatus shown in Fig. l, together with an automatic closing of the throttle and sanding of the rail surface in the event of a wheel slip condition without eiort on the part of the operator.

Having described two embodiments of our invention and illustrated each by a specific construction, it is not our intention to be limited to Yeither of the particular embodiments or to the arrangement shown or otherwise than by the spirit and scope of our appended claims.

Having now described our invention, whatwe desire to secure by Letters Patent, is:

1. A control apparatus for the usual throttle on each of a plurality of locomotive power units comprising a throttle control motor on each unit operable in accordance with pressure of iiuid to correspondingly regulate the respective throttle and thereby the propulsion power on each unit, a single operators control device connected to all of the throttle control motors for varying the pressure of fluid therein, in a range to provide full range of adjustment of said throttles, valve means controlling communication between said operators control device and all of the throttle control motors and selectively operable to disconnect any one of the motors from said operators control device and to release fluid under pressure from the disconnected motor and Vsanding control means associated with each locomotive unit operable by fluid under pressure released from the respective throttle control motor.

2., A throttle control apparatus'for a pluralitt7 of locomotive engines each having the usual individual throttle, comprisingV in combination,a

2o power motor for adjusting each throttle throughout its full range of adjustment, each motor comprising a power portion for adjusting the respective throttle, an intercepting valve, and a pilot portion responsive to pressure of uid in an adjust communication to control said power portion according to the pressure of such fluid, an operators control device operative at all times for controlling the fluid pressure in said communication, each intercepting valve being operative to disconnect the respective pilot portion from said communication and to vent fluid under pressure from the respective pilot portion, a wheel slip detecting device for each engine means for effecting operation of the respective intercepting valve to vent fluid under pressure from the respective pilot portion in response to operation of the respective wheel slip device, manually operable valve means selectively operable to cause operation of any one of the intercepting valves to vent liuid under pressure from the respective pilot portion, and means for reopening the throt" tle upon termination of operation of said wheel slip device or manually operable valve means.

3. A control apparatus for a plurality of railway prime movers comprising for each prime mover the usual throttle and a power control means operable by fluid under pressure to vary the position of said throttle and thereby the power output of the prime mover over its full range in proportion to theV pressure of such iiuid,

an operators control device for regulating the Y pressure of fluid in all of said power control means in unison, individual operators controlled means for each of said power control means normally rendering the respective power control means controllable by said control device and also operable to disconnect the respective power control means from said control device and to release iiuid under pressure therefrom, and rail sanding means fo reach prime mover arranged for operation by fluid under pressure released from the respective power control means by the respective individual operators controlled means.

4. A control apparatus for a plurality of rail" way prime movers comprising for each prime mover the usual throttle and a power control means operable by lluiol under pressure to vary the position of said throttle and thereby the power output of the prime mover over its full range in proportion to the pressure of such fluid, an `operators control device for regulating the pressure of fluid in all of said power control means in unison, individual operators controlled means for each of said power control means normally rendering the respective power control means controllable by said control device and also operable to disconnect the respective power control means from said control device and to release fluid under pressure therefrom, iluid pressure operable rail sanding means for each prime mover, and means for either preventing or permitting iiow to the respective rail sanding means of fluid under pressure released from the respective power control means by operation of the respective individual operators controlled means 5. A control apparatus for a plurality of prime vmovers comprising for each prime mover the usual throttle and throttle control means hav ing a power 01T position and a power on position and adjustable out of said power o i position upon supply of iluid under pressure to one charnber, when iluid under pressure is released from a second chamber, to correspondingly adjust said throttle for thereby varying the power output of the respective prime mover in proportion to the pressure of fluid in said one chamber and operable to said power off position upon supply ci fluid under pressure to said second chamber and release of fluid under pressure from said one chamber to close said throttle, an operators control device for controlling pressure of fluid in said one chamber in all of the throttle control means in unison, intercepting means for each throttle control means having one position for venting the respective second chamber and for establishing a communication to the respective one chamber to render the pressure of fluid t erein controllable by said operators control device, and having a second position for supplying fluid under pressure to said second chamber and for venting said one chamber, and an individual op erators control means for each intercepting means normally conditioned to effect movement of the respective intercepting means to its one position and operable to eieot movement of thc respective intercepting means to its second position.

6. A control apparatus for the usual throttles o1" a plurality of prime movers comprising for each throttle, throttle control means having a power on position and adjustable out of said power olf position upon supply of iluid under pressure to one chamber, when fluid under pressure is released. from a second chamber, to posin tion the respective throttle for varying the power output of the respective prime mover in propor tion to the pressure of iiuid in said one chamber and operable to said power off position upon supply of fluid under pressure to said second chamber and release of fluid under pressure from said one chamber, an operators control device for controlling pressure of uid in said one chamber in all of the throttle control means in unison, intercepting means for each throttle control means having one position for venting the respective second chamber and for establishing a communication to the respective one chamber to render the pressure of uid therein controllable by said operators control device, and having a second position for supplying fluid under pressure to said second chamber and for venting said one chamber, and wheel slip responsive means for each prime mover operable upon slipping of a wheel of the respective prime mover to eiect movement of the respective intercepting means to its second position.

7. In a control apparatus for the usual throttles of a plurality of engines, in combination, a

positioning motor for the throttle of each engine operative by fluid pressure to open said throttle, an operators valve device operative to supply fluid under pressure to all of the throttle motors, and mechanism comprising valve means controlling separate communications from said valve device to all of said motors and operative by manual pressure to selectively close the said communication to any one of said motors and to release iluid under pressure from the respective motor to cause closing of the respective throttle,

and means operative upon relief of manual pres sure on said valve means to actuate said valve means to open the communication closed by manual pressure on said valve means;

8. 1n a control apparatus for the usual throttles of a plurality of engines, in combination, a positioning motor for the throttle of each engine operative by fluid pressure to open said throttle, an operators valve device operative to supply fluid under pressure to all of the throttle motors, mechanism comprising valve means norrnall?,7 biased to establish communications from said valve device to all of said motors, and operative by manual pressure to selectively close the said communication to any one of said motors and to release fluid under pressure from the respective motor to cause closing or the respec tive throttle, and rail sanding means associated with each engine operable by fluid under pressure released from the respective throttle motor.

9. Apparatus for controlling the usual throttle on each engine of a multi-engine locomotive, comprising in combination, a motor for each en'- gine throttle comprising a power portion con-y nected to the throttle and having a throttle closed position and movable by uid under pressure out of said position to an extent proportionate to the pressure of such iluid to correspondingly open the respective throttle, means operative upon release of said fluid under pressure from said power portion to move same to a throttle closed position to correspondingly position the respective throttle, each motor further comprising a pilot portion operative by fluid under pressure to provide fluid to said power portion at a pressure corresponding to actuating pressure on said pilot portion, a throttle control pipe, an operators control device connected to said pipe for either venting said pipe or providing uid at different pressures in said pipe, and valve mechanism normally establishing a separate communication between said pipe and each pilot portion and operative by manual pressure to close such communication and establish a fluid pressure venting communication from the respective pilot portion.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 905,589 Ross Dec. 1, 1908 1,057,941 Crawford Apr. 1, 1913 2,170,766 Rieger Aug. 22, 1939 2,197,731 Nonemaker et al. Apr. 16, 1940 2,198,022 Aikman Apr. 28, 1940 2,198,031 Farmerc Apr. 23, 1940 2,288,173 Wohanka June 30, 1942 2,299,887 Fell Oct. 27, 1942 2,321,059 Anderson June 8, 1943 2,383,277 Stevens Aug. 21, 1945 2,404,545 Stevens July 23, 1946 2,406,264 Stevens Aug. 20, 1946 2,408,098 Schon Sept. 24, 1946 2,512,035 Newell June 20, 1950 

